Seat belt retractor having detection device

ABSTRACT

A seat belt retractor has a frame, a retracting device and a detection device. The retracting device is mounted on the frame and has a spool and a webbing body. The spool is pivotally connected to the frame. The webbing body is wound on the spool and forms multiple webbing layers around the spool. The detection device is mounted on the frame and has a detecting rod. The detecting rod is restorable, abuts an outermost webbing layer around the spool, and produces a displacement according to the variation in quantity of the webbing layers. The detection device of the seat belt retractor can directly detect a pulled length of the webbing body to know whether the user fastens the seat belt. The seat belt retractor can effectively remind a user to fasten the seat belt.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to a seat belt retractor, and more particularly to a seat belt retractor that has a detection device to detect whether a webbing body of the seat belt is pulled out or not.

2. Description of Related Art

Every occupant in a vehicle is required to fasten a seat belt for safety. The conventional seat belt has a buckle assembly, a webbing body, a tongue, and a detection device. The tongue is mounted on the webbing body and is selectively locked into the buckle assembly. The detection device is mounted on the buckle assembly to detect whether the tongue is locked or not. If the tongue is not locked into the buckle assembly, the detection device sends a signal to a controller of the vehicle, and then a light or a sound generated by the vehicle reminds the occupants in the vehicle to fasten the seat belt.

Some drivers and passengers, as a matter of convenience, use an auxiliary tongue for inserting into the buckle assembly. Though the drivers and passengers do not actually fasten the seat belts, the detection device does not send the signal to the controller of the vehicle. Therefore, the reminding function of the detection device mounted on the buckle assembly is not effectively performed.

To overcome the shortcomings, the present invention provides a seat belt retractor having a detection device to obviate the aforementioned problems.

SUMMARY OF THE INVENTION

The objective of the invention is to provide a seat belt retractor to resolve the drawbacks of the conventional detection device.

The seat belt retractor has a frame, a retracting device and a detection device. The retracting device is transversally mounted on the frame and has a spool and a webbing body. The spool is pivotally connected to the frame. The webbing body is wound on the spool and forms multiple webbing layers around the spool. The detection device is mounted on the frame and has a detecting rod. The detecting rod is restorable, abuts an outermost webbing layer around the spool, and produces a displacement according to the variation in quantity of the webbing layers.

If a user does not fasten a seat belt, the webbing body is not pulled out and the pulled length of the webbing body does not reduce. The detecting rod does not produce displacement. The detection device sends a signal to the controller of the vehicle. Then, a light or a sound generated by the vehicle can remind the user to fasten the seat belt. If the user can pull out certain length of the webbing body of a seat belt and the layer number of the webbing layers is reduced adequately. The detecting rod still abuts the outermost webbing layer around the spool and produces adequate displacement accordingly. The detection device sends another signal to a controller of a vehicle that detecting rod has displacement. The controller is aware the user has fastened the seat belt. The light or the sound generated by the vehicle can be stopped.

Therefore, the detection device of the seat belt retractor can directly detect a pulled length of the webbing body to know whether the user actually fastens the seat belt or not. The seat belt retractor can effectively remind the user to fasten the seat belt.

Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of a seat belt retractor in accordance with the present invention;

FIG. 2 is another perspective view of the seat belt retractor in FIG. 1;

FIG. 3 is an operational side view in partial section of the seat belt retractor in FIG. 1, showing a webbing body is un-pulled;

FIG. 4 is an operational side view of the seat belt retractor in FIG. 1, showing a webbing body is pulled;

FIG. 5 is a perspective view of a second embodiment of a seat belt retractor in accordance with the present invention;

FIG. 6 is another perspective view of the seat belt retractor in FIG. 5;

FIG. 7 is an operational side view in partial section of the seat belt retractor in FIG. 5, showing a webbing body is un-pulled;

FIG. 8 is an operational side view in partial section of the seat belt retractor in FIG. 5, showing a webbing body is pulled;

FIG. 9 is a perspective view of a third embodiment of a seat belt retractor in accordance with the present invention;

FIG. 10 is a side view in partial section of the seat belt retractor in FIG. 9;

FIG. 11 is a top view of the seat belt retractor in FIG. 9;

FIG. 12 is a side view of the seat belt retractor in FIG. 9, showing a webbing body is pulled;

FIG. 13 is a top view of the seat belt retractor in FIG. 9, showing a webbing body is pulled;

FIG. 14 is a side view in partial section of a fourth embodiment of a seat belt retractor in accordance with the present invention;

FIG. 15 is a side view in partial section of a fifth embodiment of a seat belt retractor in accordance with the present invention; and

FIG. 16 is an operational side view in partial section of the seat belt retractor in FIG. 15, showing a webbing body is pulled.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIGS. 1 and 2, a first embodiment of a seat belt retractor in accordance with the present invention comprises a frame 10, a retracting device 20, and a detection device 40 a.

With reference to FIGS. 1 and 2, in the first embodiment of the seat belt retractor, the frame 10 may be U-shaped and has a bottom and two opposite sides. The retracting device 20 is transversally mounted on the frame 10 and is above the bottom of the frame 10, is rotatably connected to the two opposite sides of the frame 10, and has a spool 21 and a webbing body 30. The spool 21 is pivotally connected to the two opposite sides of the frame 10. With reference to FIG. 3, the webbing body 30 is wound on the spool 21 between the two opposite sides of the frame 10 to form multiple webbing layers 31 around the spool 21 above the bottom of the frame 10.

The detection device 40 a is mounted on the frame 10 and has a detecting rod 41 a. The detecting rod 41 a is restorable, abuts an outermost webbing layer 31 around the spool 21, and produces a displacement according to the variation in quantity of the webbing layers 31.

With reference to FIGS. 1 to 4, the detection device 40 a has a micro switch 42 a mounted on the bottom of the frame 10. The detecting rod 41 a has a shaft 43 a, a torsion spring 44 a, a first rod portion 45 a, and a second rod portion 46 a. The shaft 43 a is rotatably connected to one of the two opposite sides of the frame 10 and has an outer end extending out of said one of the two opposite sides of the frame 10. The torsion spring 44 a is mounted around the outer end of the shaft 43 a. The first rod portion 45 a is formed on the shaft 43 a between the two opposite sides of the frame 10 and abuts the outermost webbing layer 31 around the spool 21. The second rod portion 46 a is above the micro switch 42 a and formed on, and protrudes from the shaft 43 a. The second rod portion 46 a selectively actuates the micro switch 42 a. An angle is formed between the second rod portion 46 a and the first rod portion 45 a.

With reference to FIGS. 3 and 4, a user can pull out the webbing body 30 that is wound on the spool 21 of the seat belt retractor, and the layer number of the webbing layers 31 is reduced. The first rod portion 45 a still abuts an outermost webbing layer 31 around the spool 21. The detecting rod 41 a is rotated in a clockwise direction and the second rod portion 46 a is also rotated in a clockwise direction. When the webbing body 30 is pulled out of the seat belt retractor for a certain length, the layer number of the webbing layers 31 is reduced to a certain degree. The second rod portion 46 a is disengaged from an actuating button 47 of the micro switch 42 a, and a signal generated by the micro switch 42 a is sent to a controller of a vehicle.

If the user does not fasten a seat belt, the webbing body 30 is not pulled out or the pulled length of the webbing body 30 is inadequate. The second rod portion 46 a still abuts the actuating button 47 of the micro switch 42 a, and then another signal generated by the micro switch 42 a is sent to the controller of the vehicle. Then, a light or a sound generated by the vehicle can remind the user to fasten the seat belt. If the webbing body 30 is pulled by the user, the second rod portion 46 a is disengaged from the actuating button 47 of the micro switch 42 a. The light or the sound generated by the vehicle can be stopped.

With reference to FIGS. 5 to 8, in a second embodiment of a seat belt retractor in accordance with the present invention, the detection device 40 b has a magnetic reed switch 42 b mounted in the frame 10. The detecting rod 41 b has a shaft 43 b, a torsion spring 44 b, a first rod portion 45 b, and a second rod portion 46 b. The shaft 43 b is rotatably connected to one of the two opposite sides of the frame 10 and has an outer end extending out of said one of the two opposite sides of the frame 10. The torsion spring 44 b is mounted around the outer end of the shaft 43 b. The first rod portion 45 b is formed on the shaft 43 b and abuts the outermost webbing layer 31 around the spool 21. The second rod portion 46 b is above the magnetic reed switch 42 b and formed on, and protrudes from the shaft 43 b and selectively actuates the magnetic reed switch 42 b. An angle is formed between the second rod portion 46 b and the first rod portion 45 b.

With reference to FIGS. 7 and 8, if the user does not fasten the seat belt, the webbing body 30 is not pulled out or the pulled length of the webbing body 30 is inadequate. The layer number of the webbing layers 31 remains unchanged or is not reduced enough. The second rod portion 46 b still abuts the magnetic reed switch 42 b, and a signal generated by the magnetic reed switch 42 b is sent to the controller of the vehicle. The vehicle gives off an alarm to remind the user to fasten the seat belt. If the webbing body 30 is pulled out by the user and the user already fastens the seat belt, the pulled length of the webbing body 30 is adequate, and the layer number of the webbing layers 31 is reduced enough. The first rod portion 45 b still abuts one of the webbing layers 31. The detecting rod 41 b is rotated in a clockwise direction. The second rod portion 46 b is rotated in a clockwise direction and is disengaged from the magnetic reed switch 42 b. Another signal generated by the magnetic reed switch 42 b is sent to the controller of the vehicle for stopping the alarm given off by the vehicle.

With reference to FIGS. 3 and 7, in the first and second embodiments of the seat belt retractor in accordance with the present invention, the frame 10 of the seat belt retractor has a protrusion 11. The protrusion 11 is mounted on the frame 10 and is above the second rod portion 46 a, 46 b. The protrusion 11 is to position the second rod portion 46 a, 46 b.

With reference to FIGS. 9 to 13, in a third embodiment of a seat belt retractor in accordance with the present invention, the detection device 40 c has a casing 42 c, a chamber, two sliding slots 43 c, and a restoring element 45 c. The casing 42 c is mounted on the frame 10 and has two opposite sidewalls. The chamber is formed in the casing 42 c. The sliding slots 43 c are elongated, are respectively formed through the two opposite sidewalls of the casing 42 c, and communicate with the chamber. The detecting rod 41 c is moveably connected to the casing 42 c along the sliding slots 43 c and has a pushing portion 44 c. The pushing portion 44 c is mounted on the detecting rod 41 c outside the casing 42 c and abuts an outermost webbing layer 31 around the spool 21. The restoring element 45 c is a spring, is mounted in the casing 42 c, and abuts the casing 42 c and the detecting rod 41 c.

With reference to FIGS. 10 to 13, if the user fastens the seat belt, the webbing body 30 is pulled out and the layer number of the webbing layers 31 is reduced. The pushing portion 44 c pushed by the restoring element 45 c is moved along the sliding slots 43 c and still abuts the webbing body 30. The pushing portion 44 c moves for an adequate displacement. The detection device 40 c sends a signal to the controller of the vehicle. If the user does not fasten the seat belt, the pushing portion 44 c does not move for an adequate displacement. Another signal generated by the detection device 40 c is sent to the controller of the vehicle. The vehicle gives off an alarm to remind the user to fasten the seat belt.

With reference to FIG. 14, in a fourth embodiment of a seat belt retractor in accordance with the present invention, the detection device 40 d has a seat 42 d, a button 43 d, and a compression spring 45 d. The seat 42 d is mounted on the bottom of the frame 10 and has an inner side facing the webbing body 30. The button 43 d is mounted on the inner side of the seat 42 d. The detecting rod 41 d is pivotally connected to the inner side of the seat 42 d and has a first end, a second end, and a pressing portion 44 d. The first end of the detecting rod 41 d is pivotally connected to the seat 42 d. The second end of the detecting rod 41 d is opposite to the first end. The pressing portion 44 d is mounted on the second end and abuts an outermost webbing layer 31 around the spool 21. The detecting rod 41 d selectively actuates the button 43 d. The compression spring 45 d is mounted between the seat 42 d and the detecting rod 41 d.

With reference to FIG. 14, if the user fastens the seat belt, the webbing body 30 is pulled out, and the layer number of the webbing layers 31 is reduced. The pressing portion 44 d is rotated in a clockwise direction and still abuts the webbing body 30. The detecting rod 41 d is disengaged from the button 43 d of the seat 42 d. A signal generated by the detection device 40 d is sent to the controller of the vehicle that user has fasten the seat belt. If the user does not fasten the seat belt, the detection device 40 d sends another signal to the controller of the vehicle, and then the vehicle gives off an alarm to remind the user to fasten the seat belt.

With reference to FIGS. 15 and 16, in a fifth embodiment of a seat belt retractor in accordance with the present invention, the detection device 40 e has a safety switch 42 e. The safety switch 42 e is mounted in the frame 10 and has a top, a sensing slot 48 e, and two sensing spots 47 e. The sensing slot 48 e is transversally formed through the top of the safety switch 42 e and has two opposite inner sides. The sensing spots 47 e are respectively mounted on the opposite inner sides of the sensing slot 48 e and face each other. The detecting rod 41 e has a shaft 43 e, a torsion spring 44 e, a first rod portion 45 e, and a second rod portion 46 e. The shaft 43 e is rotatably connected to one of the two opposite sides of the frame 10 and has an outer end extending out of said one of the two opposite sides of the frame 10. The torsion spring 44 e is mounted around the outer end of the shaft 43 e. The first rod portion 45 e is formed on the shaft 43 e and abuts an outermost webbing layer 31 around the spool 21. The second rod portion 46 e is formed on and protrudes from the shaft 43 e, is selectively inserted into the sensing slot 48 e, and selectively actuates and deactivates the sensing spots 47 e of the safety switch 42 e. An angle is formed between the second rod portion 46 e and the first rod portion 45 e.

With reference to FIG. 15, if the user does not fasten the seat belt, the first rod portion 45 e abuts the webbing body 30. The second rod portion 46 e is inserted into the sensing slot 48 e of the safety switch 42 e and is located between the two sensing spots 47 e. The two sensing spots 47 e are blocked by the second rod portion 46 e. A signal generated by the safety switch 42 e is sent to the controller of the vehicle, and the vehicle gives off an alarm to remind the user to fasten the seat belt. If the user fastens the seat belt, the webbing body 30 is pulled out. The first rod portion 45 e still abuts the webbing body 30 and is rotated. The second rod portion 46 e is rotated, too. The two sensing spots 47 e face each other and are not blocked by the second rod portion 46 e. The safety switch 42 e sends another signal to the controller of the vehicle that the user already fastens the seat belt. Therefore, the vehicle does not give off the alarm.

Accordingly, the detecting rod 41 a, 41 b, 41 c, 41 d, 41 e of the detection device 40 a, 40 b, 40 c, 40 d, 40 e can detect a pulled length of the webbing body 30 to know whether the user fastens the seat belt or not. If the user does not fasten the seat belt, the detection device 40 a, 40 b, 40 c, 40 d, 40 e can send the signal to the controller of the vehicle, and the vehicle can give off the alarm to remind the user to fasten the seat belt for enhancing the safety.

Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A seat belt retractor comprising: a frame; a retracting device transversally mounted on the frame and having a spool pivotally connected to the frame; and a webbing body wound on the spool and forming multiple webbing layers around the spool; and a detection device mounted on the frame and having a detecting rod being restorable, the detecting rod abutting an outermost webbing layer around the spool and generating a displacement according to the variation in quantity of the webbing layers.
 2. The seat belt retractor as claimed in claim 1, wherein the frame has a bottom and two opposite sides; the detection device has a micro switch mounted on the bottom of the frame; and the detecting rod has a shaft rotatably connected to one of the two opposite sides of the frame and having an outer end extending out of said one of the two opposite sides of the frame; a torsion spring mounted around the outer end of the shaft; a first rod portion formed on the shaft between the two opposite sides of the frame and abutting the outermost webbing layer around the spool; and a second rod portion above the micro switch and formed on, and protruding from the shaft, the second rod portion selectively actuating the micro switch.
 3. The seat belt retractor as claimed in claim 1, wherein the frame has two opposite sides; the detection device has a magnetic reed switch mounted on the frame; the detecting rod has a shaft rotatably connected to one of the two opposite sides of the frame and having an outer end extending out of said one of the two opposite sides of the frame; a torsion spring mounted around the outer end of the shaft; a first rod portion formed on the shaft and abutting the outermost webbing layer around the spool; and a second rod portion above the magnetic reed switch and formed on, and protruding from the shaft, the second rod selectively actuating the magnetic reed switch.
 4. The seat belt retractor as claimed in claim 2, wherein the frame of the seat belt retractor has a protrusion mounted on the frame, and the protrusion is above the second rod portion.
 5. The seat belt retractor as claimed in claim 3, wherein the frame of the seat belt retractor has a protrusion mounted on the frame, and the protrusion is above the second rod portion.
 6. The seat belt retractor as claimed in claim 1, wherein the detection device has a casing mounted on the frame and having two opposite sidewalls; a chamber formed in the casing; and two sliding slots being elongated, respectively formed through the two opposite sidewalls of the casing, and communicating with the chamber; the detecting rod is moveably connected to the casing along the sliding slots and has a pushing portion mounted on the detecting rod outside the casing and abutting the outermost webbing layer around the spool; and a restoring element is mounted in the casing and abuts the casing and the detecting rod.
 7. The seat belt retractor as claimed in claim 1, wherein the detection device has a seat mounted on a bottom of the frame and having an inner side facing the webbing body; and a button mounted on the inner side of the seat; the detecting rod is pivotally connected to the inner side of the seat, selectively actuates the button and has a first end pivotally connected to the seat; a second end opposite to the first end; and a pressing portion mounted on the second end and abutting the outermost webbing layer around the spool; and a compression spring is mounted between the seat and the detecting rod.
 8. The seat belt retractor as claimed in claim 1, wherein the frame has two opposite sides; the detection device has a safety switch mounted in the frame and having a top; a sensing slot transversally formed through the top of the safety switch and having two opposite inner sides; two sensing spots respectively mounted on the two opposite inner sides of the sensing slot and facing each other; and the detecting rod has a shaft rotatably connected to one of the two opposite sides of the frame and having an outer end extending out of said one of the opposite sides of the frame; a torsion spring mounted around the outer end of the shaft; a first rod portion formed on the shaft between the two opposite sides of the frame and abutting the outermost webbing layer around the spool; and a second rod portion formed on and protruding from the shaft, the second rod portion selectively inserted into the sensing slot and selectively actuating and deactivating the sensing spots of the safety switch. 